CPC H01J 37/32715 (2013.01) [H01J 2237/2007 (2013.01)] | 7 Claims |
1. An electrostatic chuck, comprising:
a ceramic dielectric substrate including
a first major surface on which an object of clamping is placed, and
a second major surface at a side opposite to the first major surface;
a base plate supporting the ceramic dielectric substrate, the base plate including
an upper surface at the ceramic dielectric substrate side, and
a lower surface at a side opposite to the upper surface;
a bonding part located between the ceramic dielectric substrate and the base plate;
a gas inlet path extending through the ceramic dielectric substrate, the base plate, and the bonding part, the gas inlet path including
a first hole part positioned at the ceramic dielectric substrate,
a second hole part positioned at the base plate, and a third hole part positioned at the bonding part;
a counterbore part located in at least one of the first hole part or the second hole part; and
a ceramic porous part located in the counterbore part,
the ceramic porous part including an exposed surface exposed in the third hole part,
a first direction being a direction from the base plate toward the ceramic dielectric substrate,
a second direction being a direction substantially orthogonal to the first direction,
the ceramic porous part including
a porous portion that is gas-permeable, and
a dense portion that is denser than the porous portion,
the dense portion covering an outer circumference of the porous portion,
at least a part of the dense portion including a first protruding part protruding toward the third hole part along the first direction from the exposed surface.
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